1. Field of the Invention
The present invention relates to a heterocyclic compound and an organic light emitting device including the same, and more particularly, to a heterocyclic compound having two pyrrole rings fused with a benzene ring.
2. Description of the Related Art
Electroluminescent emitting devices, which are self-emitting devices, have the advantages of having wide viewing angles, excellent contrast and quick response time, and thus have received a lot of public attention. An electroluminescent emitting device can be classified into two types, an inorganic light emitting device which includes an inorganic compound in an emission layer, and an organic light emitting device (OLED) which includes an organic compound in an emission layer. An OLED has higher brightness, lower operating voltage, quicker response time, and can realize more colors compared to an inorganic light emitting device, and thus much research thereon has been carried out.
Typically, an OLED has an anode/organic emission layer/cathode structure. An OLED can also have various other structures such as an anode/hole transport layer/organic emission layer/cathode structure and an anode/hole transport layer/organic emission layer/electron transport layer/cathode structure by interposing a hole injection layer and/or a hole transport layer and electron injection layer between the anode and the emission layer or between the emission layer and the cathode.
A polyphenyl compound or an anthracene derivative is known as a material used to form a hole transport layer (U.S. Pat. Nos. 6,596,415 and 6,465,115). However, characteristics of organic light emitting devices formed of materials that are conventionally used to form a hole injection and/or transport layer such as lifetime, efficiency and power consumption are not satisfactory. Thus, there is a need to improve those characteristics of organic light emitting devices.